In this paper,a novel train positioning method considering satellite raw observation data was proposed,which aims to promote train positioning performance from an innovative perspective of the train satellite-based po...In this paper,a novel train positioning method considering satellite raw observation data was proposed,which aims to promote train positioning performance from an innovative perspective of the train satellite-based positioning error sources.The method focused on overcoming the abnormal observations in satellite observation data caused by railway environment rather than the positioning results.Specifically,the relative positioning experimental platform was built and the zero-baseline method was firstly employed to evaluate the carrier phase data quality,and then,GNSS combined observation models were adopted to construct the detection values,which were applied to judge abnormal-data through the dual-frequency observations.Further,ambiguity fixing optimization was investigated based on observation data selection in partly-blocked environments.The results show that the proposed method can effectively detect and address abnormal observations and improve positioning stability.Cycle slips and gross errors can be detected and identified based on dual-frequency global navigation satellite system data.After adopting the data selection strategy,the ambiguity fixing percentage was improved by 29.2%,and the standard deviation in the East,North,and Up components was enhanced by 12.7%,7.4%,and 12.5%,respectively.The proposed method can provide references for train positioning performance optimization in railway environments from the perspective of positioning error sources.展开更多
AIM To determine whether oral glutathione(GSH)administration can alleviate the effects of fasting-induced intestinal atrophy in the small intestinal mucosa. METHODS Rats were divided into eight groups.One group was fe...AIM To determine whether oral glutathione(GSH)administration can alleviate the effects of fasting-induced intestinal atrophy in the small intestinal mucosa. METHODS Rats were divided into eight groups.One group was fed ad libitum,another was fed ad libitum and received oral GSH,and six groups were administrated saline(SA)or GSH orally during fasting.Mucosal height,apoptosis,and cell proliferation in the jejunum were histologically evaluated.i NOS protein expression(by immunohistochemistry),nitrite levels(by high performance liquid chromatography,as a measure of NO production),8-hydroxydeoxyguanosine formation(by ELISA,indicating ROS levels),glutathione/oxidized glutathione(GSH/GSSG)ratio(by enzymatic colorimetric detection),andγ-glutamyl transpeptidase(Ggt1)mR NA levels in the jejunum(by semi-quantitative RT-PCR)were also estimated. RESULTS O r a l G S H a d m i n i s t r a t i o n w a s d e m o n s t r a t e d t o drastically reduce fasting-induced intestinal atrophy in the jejunum.In particular,jejunal mucosal height was enhanced in GSH-treated animals compared to SA-treated animals[527.2±6.9 for 50 mg/kg GSH,567.6±5.4 for 500 mg/kg GSH vs 483.1±4.9(μm),P<0.01at 72 h].This effect was consistent with decreasing changes in GSH-treated animals compared to SA-treated animals for iN OS protein staining[0.337±0.016for 50 mg/kg GSH,0.317±0.017 for 500 mg/kg GSH vs 0.430±0.023(area of staining part/area of tissue),P<0.01 at 72 h]and NO[2.99±0.29 for 50 mg/kg GSH,2.88±0.19 for 500 mg/kg GSH vs 5.34±0.35(nmol/g tissue),P<0.01 at 72 h]and ROS[3.92±0.46for 50 mg/kg GSH,4.58±0.29 for 500 mg/kg GSH vs6.42±0.52(8-OHdG pg/μg DNA),P<0.01,P<0.05at 72 h,respectively]levels as apoptosis mediators in the jejunum.Furthermore,oral GSH administration attenuated cell proliferation decreases in the fasting jejunum[182.5±1.9 for 500 mg/kg GSH vs 155.8±3.4(5-Brd U positive cells/10 crypts),P<0.01 at 72h].Notably,both GSH concentration and Ggt1 m RNA expression in the jejunum were also attenuated in rats following oral administration of GSH during fasting as compared with fasting alone[0.45±0.12 vs 0.97±0.06(nmol/mg tissue),P<0.01;1.01±0.11 vs 2.79±0.39(Ggt1 m RNA/Gapdh m RNA),P<0.01 for 500 mg/kg GSH at 48 h,respectively]. CONCLUSION Oral GSH administration during fasting enhances jejunal regenerative potential to minimize intestinal mucosal atrophy by diminishing fasting-mediated ROS generation and enterocyte apoptosis and enhancing cell proliferation.展开更多
Eucalyptus grandis W.Hill ex Maiden bark was liquefied in glycerol with two types of catalysts.The chemical components of the residues with respect to temperature were examined to investigate the liquefaction behavior...Eucalyptus grandis W.Hill ex Maiden bark was liquefied in glycerol with two types of catalysts.The chemical components of the residues with respect to temperature were examined to investigate the liquefaction behavior of bark.The results reveal that sulfuric acid was more efficient in converting bark into fragments in glycerol at low temperatures B 433.15 K,equivalent to 160C than phosphoric acid.The liquefaction order of chemical components was lignin,hemicelluloses,and cellulose.The decrease of liquefaction yields at high temperatures(≤453.15 K)catalyzed by sulfuric acid was possibly a result of the recondensation of lignin and/or hemicelluloses.展开更多
Bio-based phenol-formaldehyde polymer (BioNovolac) was developed by reacting molar excess of bio-oil/phenolwith formaldehyde in acidic medium. Glycidyl 3,5-diglycidoxybenzoate (GDGB), was prepared by directglycidylati...Bio-based phenol-formaldehyde polymer (BioNovolac) was developed by reacting molar excess of bio-oil/phenolwith formaldehyde in acidic medium. Glycidyl 3,5-diglycidoxybenzoate (GDGB), was prepared by directglycidylation of α-resorcylic acid (RA), a naturally occurring phenolic monomer. GDGB was crosslinked in thepresence of BioNovolac by anionic polymerization. Fourier transform infrared spectroscopy (FTIR) confirmedthe formation of semi-interpenetrating polymer networks. The glass transition temperature and moduli of biobasedcrosslinked systems were observed to increase with increasing GDGB content. Active chain density andmass retention measured by dynamic mechanical analysis (DMA) and Soxhlet extraction, respectively, indicated ahigh crosslink density of the cured networks. Scanning electron microscopy (SEM) images depicted thehomogeneity of the bulk phase. The preparation of bio-based epoxy-novolac thermoset network resulted inreduced consumption of petroleum-based chemicals.展开更多
Bacteria play a major role in metabolizing ammonia and other metabolites in recirculating aquaculture systems(RASs).To characterize and compare the bacterial communities in the biofilters of two full-scale RASs for th...Bacteria play a major role in metabolizing ammonia and other metabolites in recirculating aquaculture systems(RASs).To characterize and compare the bacterial communities in the biofilters of two full-scale RASs for the culture of puffer fish,Takifugu rubripes,at different ages and densities were studied.In overall,47807 optimized reads of the 16 S rRNA gene with V4-V5 region were obtained from four biofilm samples collected after biofilm maturation.At 97%cut-off level,these sequences were clustered into 500 operational taxonomic units,and were classified into 19 bacterial phyla and 138 genera.At the phylum level,Proteobacteria and Bacteroidetes were the most abundant,followed by Nitrospirae and Planctomycetes.At the genus level,Colwellia,Marinifilum,Oceanospirillum,Lutibacter,Winogradskyella,Pseudoalteromonas,Arcobacter,and Phaeobacter were the top members.Nitrosomonas and Nitrospira were main ammonia-and nitrite-oxidizing bacteria.Differences in bacterial communities at different sampling dates and similarities of both biofilters were revealed in the Venn diagram and cluster analysis.Maintaining a good water quality and health offarmed fish in RASs depended on the correct management of the bacterial communities.This study provides more accurate information on the bacterial communities associated with the bifilters of both RASs.展开更多
Photosynthesis is the basis of plant growth and development as well as the existence of the biological world. Photosynthesis is of great theoretical and practical significance. In this paper, the effects of temperatur...Photosynthesis is the basis of plant growth and development as well as the existence of the biological world. Photosynthesis is of great theoretical and practical significance. In this paper, the effects of temperature, drought, salt, light and other abiotic stress factors on plant photosynthesis were reviewed.展开更多
Tree improvement programs on loblolly pine(Pinus taeda) in the southeastern USA has focused primarily on improving growth, form, and disease tolerance.However, due to the recent reduction of design values for visually...Tree improvement programs on loblolly pine(Pinus taeda) in the southeastern USA has focused primarily on improving growth, form, and disease tolerance.However, due to the recent reduction of design values for visually graded southern yellow pine lumber(including loblolly pine), attention has been drawn to the material quality of genetically improved loblolly pine. In this study,we used the time-of-flight(TOF) acoustic tool to assess the effect of genetic families on diameter, slenderness, fiber length, microfibril angle(MFA), velocity and dynamic stiffness estimated using green density(DMOEG) and basic density(DMOEB) of 14-year-old loblolly pine stands selected from two sites. All the 184 and 204 trees of the selected eight half-sib genetic families on sites 1 and 2 respectively were tested using TOF acoustic tool, and two 5 mm core samples taken at breast height level(1.3 m)used to for the anatomical and physical properties analysis.The results indicated a significant positive linear relationship between dynamic MOEs(DMOEGand DMOEB)versus tree diameter, slenderness, and fiber length while dynamic MOEs negatively but nonsignificant correlated with MFA. While there was no significant difference in DMOEBbetween sites; velocity 2 for site 1 was significantly higher than site 2 but DMOEGwas higher for site 2 than site 1. Again, the mean DMOEGand DMOEBreported in the present study presents a snapshot of the expected static MOE for green and 12% moisture conditions respectively for loblolly pine. Furthermore, there were significant differences between families for most of the traits measured and this suggests that forest managers have the opportunity to select families that exhibit the desired fiber morphology for final product performance. Lastly,since the dynamic MOE based on green density(DMOEG),basic density(DMOEB) and velocity 2 present difference conclusions, practitioners of this type of acoustic technique should take care when extrapolating results across the sites.展开更多
By measuring water temperature,salinity,pH,dissolved oxygen,nitrite and ammonia nitrogen,the annual variation regularity of water quality in the aquaculture ponds for sea cucumbers Apostichopus japonicus in Dalian wer...By measuring water temperature,salinity,pH,dissolved oxygen,nitrite and ammonia nitrogen,the annual variation regularity of water quality in the aquaculture ponds for sea cucumbers Apostichopus japonicus in Dalian were studied.Results showed that the physicochemical indicators kept changing in the year,and the various ranges of water temperature,salinity,pH,dissolved oxygen,nitrite,and ammonia nitrogen were 6.38-27.27℃,29.20‰-33.78‰,7.86-8.38,5.19-13.36 mg/L,0.0037-0.0090 mg/L and 0.0171-0.0908 mg/L,respectively.Analysis indicated that there was an extremely significant negative correlation between water temperature and dissolved oxygen(P<0.01),an extremely significant positive correlation between water temperature and ammonia nitrogen(P<0.01),a significant negative correlation between salinity and nitrite(P<0.05),a significant negative correlation between dissolved oxygen and nitrite(P<0.05),and an extremely significant negative correlation between dissolved oxygen and ammonia nitrogen(P<0.01)in the aquaculture ponds for sea cucumber in Dalian.Research showed that the water quality of aquaculture ponds kept fluctuating all the time during the tested period,there were complicated and close relationships among physicochemical indicators,and a slight variation of external factors would bring consecutive reactions to different indicators in the water quality of aquaculture ponds.A reference for the production and management of sea cucumbers could be provided from the results.展开更多
Today the Organic Rankine Cycle(ORC) is considered as one of the most promising technologies to recover the power from low-grade heat resources. In order to realize a high performance ORC turbine, the Computational Fl...Today the Organic Rankine Cycle(ORC) is considered as one of the most promising technologies to recover the power from low-grade heat resources. In order to realize a high performance ORC turbine, the Computational Fluid Dynamics(CFD) is extensively used to simulate the internal flow in the aerodynamic design. But due to the high non-ideality of the working fluid, it is crucial to take the real gas effect into consideration.In the present study, an accurate and reliable method of the perfect gas approximation for an organic working fluid(R245 fa) is developed. At first, the effectiveness of a perfect gas approximation is examined in two-dimensional CFD simulations of a convergent-divergent nozzle. Then the accuracy of the perfect gas approximation, definition of suitable nondimensional performance parameters and effective conversion method between the different gas models are studied in three-dimensional CFD simulations of an ORC radial-inflow turbine.展开更多
Forest biomass has great potential as a biofuel feedstock, but information on forest owner perceptions of using forest biomass to produce bioenergy is lacking. In this case study, we surveyed 3500 small to medium priv...Forest biomass has great potential as a biofuel feedstock, but information on forest owner perceptions of using forest biomass to produce bioenergy is lacking. In this case study, we surveyed 3500 small to medium private forest landowners in southwestern Louisiana to better understand their attitudes and perceptions towards harvesting forest biomass for bioenergy production. Results indicate that landowners: 1) were positive about utilizing biomass for bioenergy, 2) believe viable biomass conversion technologies exist, 3) had antagonistic or neutral attitudes towards some technological, economic, and policy issues associated with using forest biomass for bioenergy due in part to lack of information or knowledge, and 4) felt biomass is a low-value product compared to traditional products. Landowners’ perceptions of participating in bio-based activities and markets vary among age and ownership size, and 51% of forest landowners were willing to participate in management activities specifically geared for bioenergy production.展开更多
In order to investigate the effects of meteorological factors on rape overwintering ability,forage yield and quality of rape in the North China plain,Brassia campestris L.and Brassica napus L.were used in this study.T...In order to investigate the effects of meteorological factors on rape overwintering ability,forage yield and quality of rape in the North China plain,Brassia campestris L.and Brassica napus L.were used in this study.The results showed that compared with the B.napus L.varieties,the growth period of B.campestris L.was shortened by 10-15 d,the overwintering rate(WR)increased by 50.6%,and the density after winter(PD)increased by 41.5%.The fresh forage yield(FFY)and dry forage yield(DFY)of the B.campestris L.type significantly increased by 40.9%and 38.1%compared with the B.napus L.type.,respectively,while the forage quality of the B.napus L.type rape was significantly better than that of the B.campestris L.type.Compared with the B.campestris L.type,the crude protein(CP),fat,ash and total fatty acid(TFA)contents of the B.napus L.type of rape increased by 27.6%,42.9%,23.9%and 52.3%,respectively,and the milk productivity(HM),relative forage value(RFV)and relative forage quality(RFQ)increased by 14.0%,16.2%and 42.1%,respectively.The light and heat resources before wintering increased the WR and PD(P<0.05),and were positively correlated with FFY and DFY(P>0.05),and lower temperature during the wintering period led to lower WR(P<0.01).The light and heat resources during the overwintering period and after regreening were negatively correlated with FFY and DFY(P>0.05).The contents of CP,fat and TFA of rape had an extremely significant negative correlation with the temperature and sunshine hours before wintering,but an extremely significant positive correlation with the temperature during the wintering period and after regreening,as well as the sunshine hours and rainfall during the wintering period;and HM had an extremely significant positive correlation with the temperature,sunshine hours and rainfall during the wintering period,while RFV and RFQ were only extremely significantly positively correlated with the maximum temperature and rainfall.In summary,in the North China Plain,for autumn sowing rape,the B.campestris L.type can be selected to improve the wintering rate,and the B.napus L.type should be the main choice to improve the forage quality of rape.Therefore,the B.napus L.variety HYZ62 can be selected for autumn sowing in the North China Plain.展开更多
In the area of recycling of spent chromated copper arsenate (CCA)-treated wood, most studies to date have focused on methods of removing/extracting the residual preservative from the wood matrix. It is well recognized...In the area of recycling of spent chromated copper arsenate (CCA)-treated wood, most studies to date have focused on methods of removing/extracting the residual preservative from the wood matrix. It is well recognized that exposure of CCA-treated wood to an acid solution can reverse the CCA fixation process thereby converting the CCA elements into their water-soluble form. The economic viability of the process is enhanced because it can be integrated with other technologies and products (e.g., “green” spray foam insulation, etc.). The market for the “green” CCA is the same as for traditional CCA-the wood treating industry, principally utility poles and pilings. A market research study was conducted to determine the suitability of spent CCA-treated wood as a source for recycled, “green” CCA for manufacturing “green” spray-foam insulation. Specifically, we wanted to discern the attitudes and overall perspectives of buyers/sellers (i.e., utilities and wood treating companies) of CCA preservatives and treated wood products, disposal methods and costs for decommissioned CCA-treated wood, and understand perceptions of and willingness-to-pay for “green” CCA preservatives extracted from the technologies used in this research. Results show that 60% of wood preservative treating respondents and 60% of electric utility company respondents are somewhat or greatly interested in using out-of-service utility poles as feedstock for “green insulation” as part of a new potential business venture.展开更多
This paper combines the application direction of bamboo vinegar in daily chemicals, focusing on the performance of bamboo vinegar raw materials from different sources in antibacterial, deodorization, antimycotic, etc....This paper combines the application direction of bamboo vinegar in daily chemicals, focusing on the performance of bamboo vinegar raw materials from different sources in antibacterial, deodorization, antimycotic, etc. The results show that bamboo vinegar have a good antibacterial effect to the common Staphylococcus aureus and Escherichia coli, and also have obvious deodorant effect and a certain inhibitory effect on mold. However, under the certain low concentration, bamboo vinegar will play a role in promoting mold growth.展开更多
Objective:To determine the anti-obesity effects of oolong tea on diet-induced overweight or obesity.Methods:A total of 8 g of oolong tea a day for 6 weeks was ingested by 102 diet-induced overweight or obese subjects....Objective:To determine the anti-obesity effects of oolong tea on diet-induced overweight or obesity.Methods:A total of 8 g of oolong tea a day for 6 weeks was ingested by 102 diet-induced overweight or obese subjects.The body fat level of the subjects was determined at the same time by taking body weight, height and waist measurements.The thickness of the subcutaneous fat layer was also determined on the abdomen 3 cm to the right of the navel by the ultrasonic echo method.On the other hand,effects of oolong...展开更多
The rotational frequency noise(also known as the pulsation noise) due to the mistuning of impeller blade rows introduced at the manufacturing stage of the impellers is observed in the small-sized centrifugal compresso...The rotational frequency noise(also known as the pulsation noise) due to the mistuning of impeller blade rows introduced at the manufacturing stage of the impellers is observed in the small-sized centrifugal compressor for automobile turbochargers. The present paper addresses the elucidation of the generating mechanism and parameter dependency such as the kind and degree of mistuning. In order to analyze numerically the rotational frequency noise due to mistuning, the unsteady computational fluid dynamics(CFD) of the whole compressor including volute is executed, and the resultant time history of the pressure is fed into the spectral analysis.展开更多
Since the automobile turbochargers are installed in an engine compartment with limited space, the ducts upstream of the turbocharger compressor may be curved in a complex manner. In the present paper, the effect of a ...Since the automobile turbochargers are installed in an engine compartment with limited space, the ducts upstream of the turbocharger compressor may be curved in a complex manner. In the present paper, the effect of a curved duct upstream on performance of small centrifugal compressors for automobile turbochargers is discussed. The computational fluid dynamics (CFD) analysis of a turbocharger compressor validated for the compressor model with the straight pipe applied to the compressor with the curved pipe are executed, and the deterioration of the performance for the curved pipe is confirmed. It is also found that the deterioration of compressor performance is caused by the interaction of the secondary flow and the impeller.展开更多
In view of the risks induced by the inhibitory effects of applying impracticably large amounts of sewage sludge biochar(SSB)to the alkaline soil,this field study investigated the influence of moderate biochar amendmen...In view of the risks induced by the inhibitory effects of applying impracticably large amounts of sewage sludge biochar(SSB)to the alkaline soil,this field study investigated the influence of moderate biochar amendments(0,1500,4500,and 9000 kg/hm2)on corn growth,alkaline soil properties,and the uptake of potentially toxic elements(PTEs).The results showed that applying more SSB would decrease the ammonium nitrogen concentration and increase the available phosphorus and potassium concentrations,which inhibited corn plant growth because of high background nutrient levels of the alkaline soil.When the alkaline soil was amended with 1500 kg/hm2 SSB,the dry weight of 100 niblets increased from 32.11 g in the control to 35.07 g.There was no significant variation in the total concentration of PTEs in the soil.The concentrations of Mn,Ni,Cu,and Zn in niblets decreased from 5.54,0.83,2.26,and 27.15 mg/kg in the control to 4.47,0.62,1.30,and 23.45 mg/kg,respectively.Accordingly,the health risk from corn consumption was significantly reduced.Furthermore,the combination of SSB and fertilizer improved corn growth and reduced the risk of consumption of PTEs.Therefore,considering the increase in corn fruit yield and the decrease in consumption risk,applying 1500 kg/hm2 of biochar to alkaline soils is a realistically achievable rate,which can broaden the utilization of SSB for remediation of different types of soil.展开更多
基金Project(52272339)supported by the National Natural Science Foundation of ChinaProject(2023YFB390730303)supported by the National Key Research and Development Program of China+2 种基金Project(L2023G004)supported by the Science and Technology Research and Development Program of China State Railway Group Co.,Ltd.Project(QZKFKT2023-005)supported by the State Key Laboratory of Heavy-duty and Express High-power Electric Locomotive,ChinaProject(2022JZZ05)supported by the Open Foundation of MOE Key Laboratory of Engineering Structures of Heavy Haul Railway(Central South University),China。
文摘In this paper,a novel train positioning method considering satellite raw observation data was proposed,which aims to promote train positioning performance from an innovative perspective of the train satellite-based positioning error sources.The method focused on overcoming the abnormal observations in satellite observation data caused by railway environment rather than the positioning results.Specifically,the relative positioning experimental platform was built and the zero-baseline method was firstly employed to evaluate the carrier phase data quality,and then,GNSS combined observation models were adopted to construct the detection values,which were applied to judge abnormal-data through the dual-frequency observations.Further,ambiguity fixing optimization was investigated based on observation data selection in partly-blocked environments.The results show that the proposed method can effectively detect and address abnormal observations and improve positioning stability.Cycle slips and gross errors can be detected and identified based on dual-frequency global navigation satellite system data.After adopting the data selection strategy,the ambiguity fixing percentage was improved by 29.2%,and the standard deviation in the East,North,and Up components was enhanced by 12.7%,7.4%,and 12.5%,respectively.The proposed method can provide references for train positioning performance optimization in railway environments from the perspective of positioning error sources.
基金Supported by Kyowa Hakko Bio Co.,Ltd.to Uchida H
文摘AIM To determine whether oral glutathione(GSH)administration can alleviate the effects of fasting-induced intestinal atrophy in the small intestinal mucosa. METHODS Rats were divided into eight groups.One group was fed ad libitum,another was fed ad libitum and received oral GSH,and six groups were administrated saline(SA)or GSH orally during fasting.Mucosal height,apoptosis,and cell proliferation in the jejunum were histologically evaluated.i NOS protein expression(by immunohistochemistry),nitrite levels(by high performance liquid chromatography,as a measure of NO production),8-hydroxydeoxyguanosine formation(by ELISA,indicating ROS levels),glutathione/oxidized glutathione(GSH/GSSG)ratio(by enzymatic colorimetric detection),andγ-glutamyl transpeptidase(Ggt1)mR NA levels in the jejunum(by semi-quantitative RT-PCR)were also estimated. RESULTS O r a l G S H a d m i n i s t r a t i o n w a s d e m o n s t r a t e d t o drastically reduce fasting-induced intestinal atrophy in the jejunum.In particular,jejunal mucosal height was enhanced in GSH-treated animals compared to SA-treated animals[527.2±6.9 for 50 mg/kg GSH,567.6±5.4 for 500 mg/kg GSH vs 483.1±4.9(μm),P<0.01at 72 h].This effect was consistent with decreasing changes in GSH-treated animals compared to SA-treated animals for iN OS protein staining[0.337±0.016for 50 mg/kg GSH,0.317±0.017 for 500 mg/kg GSH vs 0.430±0.023(area of staining part/area of tissue),P<0.01 at 72 h]and NO[2.99±0.29 for 50 mg/kg GSH,2.88±0.19 for 500 mg/kg GSH vs 5.34±0.35(nmol/g tissue),P<0.01 at 72 h]and ROS[3.92±0.46for 50 mg/kg GSH,4.58±0.29 for 500 mg/kg GSH vs6.42±0.52(8-OHdG pg/μg DNA),P<0.01,P<0.05at 72 h,respectively]levels as apoptosis mediators in the jejunum.Furthermore,oral GSH administration attenuated cell proliferation decreases in the fasting jejunum[182.5±1.9 for 500 mg/kg GSH vs 155.8±3.4(5-Brd U positive cells/10 crypts),P<0.01 at 72h].Notably,both GSH concentration and Ggt1 m RNA expression in the jejunum were also attenuated in rats following oral administration of GSH during fasting as compared with fasting alone[0.45±0.12 vs 0.97±0.06(nmol/mg tissue),P<0.01;1.01±0.11 vs 2.79±0.39(Ggt1 m RNA/Gapdh m RNA),P<0.01 for 500 mg/kg GSH at 48 h,respectively]. CONCLUSION Oral GSH administration during fasting enhances jejunal regenerative potential to minimize intestinal mucosal atrophy by diminishing fasting-mediated ROS generation and enterocyte apoptosis and enhancing cell proliferation.
基金This work was partially supported by the Fundamental Research Funds for the Central Non-profit Research Institution of CAF(TGB2016001)the Key Laboratory of Wood Industry and Furniture Engineering of Sichuan Provincial Colleges and Universitiesthe National Natural Science Foundation of China(31700578).
文摘Eucalyptus grandis W.Hill ex Maiden bark was liquefied in glycerol with two types of catalysts.The chemical components of the residues with respect to temperature were examined to investigate the liquefaction behavior of bark.The results reveal that sulfuric acid was more efficient in converting bark into fragments in glycerol at low temperatures B 433.15 K,equivalent to 160C than phosphoric acid.The liquefaction order of chemical components was lignin,hemicelluloses,and cellulose.The decrease of liquefaction yields at high temperatures(≤453.15 K)catalyzed by sulfuric acid was possibly a result of the recondensation of lignin and/or hemicelluloses.
文摘Bio-based phenol-formaldehyde polymer (BioNovolac) was developed by reacting molar excess of bio-oil/phenolwith formaldehyde in acidic medium. Glycidyl 3,5-diglycidoxybenzoate (GDGB), was prepared by directglycidylation of α-resorcylic acid (RA), a naturally occurring phenolic monomer. GDGB was crosslinked in thepresence of BioNovolac by anionic polymerization. Fourier transform infrared spectroscopy (FTIR) confirmedthe formation of semi-interpenetrating polymer networks. The glass transition temperature and moduli of biobasedcrosslinked systems were observed to increase with increasing GDGB content. Active chain density andmass retention measured by dynamic mechanical analysis (DMA) and Soxhlet extraction, respectively, indicated ahigh crosslink density of the cured networks. Scanning electron microscopy (SEM) images depicted thehomogeneity of the bulk phase. The preparation of bio-based epoxy-novolac thermoset network resulted inreduced consumption of petroleum-based chemicals.
基金Supported by the National Key R&D Program of China(No.2017YFD0701700)National Natural Science Foundation of China(Nos.31472312,31672673)。
文摘Bacteria play a major role in metabolizing ammonia and other metabolites in recirculating aquaculture systems(RASs).To characterize and compare the bacterial communities in the biofilters of two full-scale RASs for the culture of puffer fish,Takifugu rubripes,at different ages and densities were studied.In overall,47807 optimized reads of the 16 S rRNA gene with V4-V5 region were obtained from four biofilm samples collected after biofilm maturation.At 97%cut-off level,these sequences were clustered into 500 operational taxonomic units,and were classified into 19 bacterial phyla and 138 genera.At the phylum level,Proteobacteria and Bacteroidetes were the most abundant,followed by Nitrospirae and Planctomycetes.At the genus level,Colwellia,Marinifilum,Oceanospirillum,Lutibacter,Winogradskyella,Pseudoalteromonas,Arcobacter,and Phaeobacter were the top members.Nitrosomonas and Nitrospira were main ammonia-and nitrite-oxidizing bacteria.Differences in bacterial communities at different sampling dates and similarities of both biofilters were revealed in the Venn diagram and cluster analysis.Maintaining a good water quality and health offarmed fish in RASs depended on the correct management of the bacterial communities.This study provides more accurate information on the bacterial communities associated with the bifilters of both RASs.
基金Supported by Science and Technology Innovation Fund of Dalian City(2019J13SN120)Guiding Project of Natural Science Foundation of Liaoning Province(20170540035)Undergraduate Innovation and Enterpreneurship Training Program of China(201911258016)
文摘Photosynthesis is the basis of plant growth and development as well as the existence of the biological world. Photosynthesis is of great theoretical and practical significance. In this paper, the effects of temperature, drought, salt, light and other abiotic stress factors on plant photosynthesis were reviewed.
基金supported by the Auburn University Intramural funds
文摘Tree improvement programs on loblolly pine(Pinus taeda) in the southeastern USA has focused primarily on improving growth, form, and disease tolerance.However, due to the recent reduction of design values for visually graded southern yellow pine lumber(including loblolly pine), attention has been drawn to the material quality of genetically improved loblolly pine. In this study,we used the time-of-flight(TOF) acoustic tool to assess the effect of genetic families on diameter, slenderness, fiber length, microfibril angle(MFA), velocity and dynamic stiffness estimated using green density(DMOEG) and basic density(DMOEB) of 14-year-old loblolly pine stands selected from two sites. All the 184 and 204 trees of the selected eight half-sib genetic families on sites 1 and 2 respectively were tested using TOF acoustic tool, and two 5 mm core samples taken at breast height level(1.3 m)used to for the anatomical and physical properties analysis.The results indicated a significant positive linear relationship between dynamic MOEs(DMOEGand DMOEB)versus tree diameter, slenderness, and fiber length while dynamic MOEs negatively but nonsignificant correlated with MFA. While there was no significant difference in DMOEBbetween sites; velocity 2 for site 1 was significantly higher than site 2 but DMOEGwas higher for site 2 than site 1. Again, the mean DMOEGand DMOEBreported in the present study presents a snapshot of the expected static MOE for green and 12% moisture conditions respectively for loblolly pine. Furthermore, there were significant differences between families for most of the traits measured and this suggests that forest managers have the opportunity to select families that exhibit the desired fiber morphology for final product performance. Lastly,since the dynamic MOE based on green density(DMOEG),basic density(DMOEB) and velocity 2 present difference conclusions, practitioners of this type of acoustic technique should take care when extrapolating results across the sites.
基金the National Oceanic and Public Research Project(201405003).
文摘By measuring water temperature,salinity,pH,dissolved oxygen,nitrite and ammonia nitrogen,the annual variation regularity of water quality in the aquaculture ponds for sea cucumbers Apostichopus japonicus in Dalian were studied.Results showed that the physicochemical indicators kept changing in the year,and the various ranges of water temperature,salinity,pH,dissolved oxygen,nitrite,and ammonia nitrogen were 6.38-27.27℃,29.20‰-33.78‰,7.86-8.38,5.19-13.36 mg/L,0.0037-0.0090 mg/L and 0.0171-0.0908 mg/L,respectively.Analysis indicated that there was an extremely significant negative correlation between water temperature and dissolved oxygen(P<0.01),an extremely significant positive correlation between water temperature and ammonia nitrogen(P<0.01),a significant negative correlation between salinity and nitrite(P<0.05),a significant negative correlation between dissolved oxygen and nitrite(P<0.05),and an extremely significant negative correlation between dissolved oxygen and ammonia nitrogen(P<0.01)in the aquaculture ponds for sea cucumber in Dalian.Research showed that the water quality of aquaculture ponds kept fluctuating all the time during the tested period,there were complicated and close relationships among physicochemical indicators,and a slight variation of external factors would bring consecutive reactions to different indicators in the water quality of aquaculture ponds.A reference for the production and management of sea cucumbers could be provided from the results.
文摘Today the Organic Rankine Cycle(ORC) is considered as one of the most promising technologies to recover the power from low-grade heat resources. In order to realize a high performance ORC turbine, the Computational Fluid Dynamics(CFD) is extensively used to simulate the internal flow in the aerodynamic design. But due to the high non-ideality of the working fluid, it is crucial to take the real gas effect into consideration.In the present study, an accurate and reliable method of the perfect gas approximation for an organic working fluid(R245 fa) is developed. At first, the effectiveness of a perfect gas approximation is examined in two-dimensional CFD simulations of a convergent-divergent nozzle. Then the accuracy of the perfect gas approximation, definition of suitable nondimensional performance parameters and effective conversion method between the different gas models are studied in three-dimensional CFD simulations of an ORC radial-inflow turbine.
文摘Forest biomass has great potential as a biofuel feedstock, but information on forest owner perceptions of using forest biomass to produce bioenergy is lacking. In this case study, we surveyed 3500 small to medium private forest landowners in southwestern Louisiana to better understand their attitudes and perceptions towards harvesting forest biomass for bioenergy production. Results indicate that landowners: 1) were positive about utilizing biomass for bioenergy, 2) believe viable biomass conversion technologies exist, 3) had antagonistic or neutral attitudes towards some technological, economic, and policy issues associated with using forest biomass for bioenergy due in part to lack of information or knowledge, and 4) felt biomass is a low-value product compared to traditional products. Landowners’ perceptions of participating in bio-based activities and markets vary among age and ownership size, and 51% of forest landowners were willing to participate in management activities specifically geared for bioenergy production.
基金National Key Research and Development Program of China(2017YFD0200808)Seed Science and Technology Major Special Program of Tianjin(18ZXZYNC00100)+1 种基金Scientific Research Program(Natural Science)of Tianjin Education Committee(2019KJ039)Graduate Research Innovation Program of Tianjin(2020YJSS128).
文摘In order to investigate the effects of meteorological factors on rape overwintering ability,forage yield and quality of rape in the North China plain,Brassia campestris L.and Brassica napus L.were used in this study.The results showed that compared with the B.napus L.varieties,the growth period of B.campestris L.was shortened by 10-15 d,the overwintering rate(WR)increased by 50.6%,and the density after winter(PD)increased by 41.5%.The fresh forage yield(FFY)and dry forage yield(DFY)of the B.campestris L.type significantly increased by 40.9%and 38.1%compared with the B.napus L.type.,respectively,while the forage quality of the B.napus L.type rape was significantly better than that of the B.campestris L.type.Compared with the B.campestris L.type,the crude protein(CP),fat,ash and total fatty acid(TFA)contents of the B.napus L.type of rape increased by 27.6%,42.9%,23.9%and 52.3%,respectively,and the milk productivity(HM),relative forage value(RFV)and relative forage quality(RFQ)increased by 14.0%,16.2%and 42.1%,respectively.The light and heat resources before wintering increased the WR and PD(P<0.05),and were positively correlated with FFY and DFY(P>0.05),and lower temperature during the wintering period led to lower WR(P<0.01).The light and heat resources during the overwintering period and after regreening were negatively correlated with FFY and DFY(P>0.05).The contents of CP,fat and TFA of rape had an extremely significant negative correlation with the temperature and sunshine hours before wintering,but an extremely significant positive correlation with the temperature during the wintering period and after regreening,as well as the sunshine hours and rainfall during the wintering period;and HM had an extremely significant positive correlation with the temperature,sunshine hours and rainfall during the wintering period,while RFV and RFQ were only extremely significantly positively correlated with the maximum temperature and rainfall.In summary,in the North China Plain,for autumn sowing rape,the B.campestris L.type can be selected to improve the wintering rate,and the B.napus L.type should be the main choice to improve the forage quality of rape.Therefore,the B.napus L.variety HYZ62 can be selected for autumn sowing in the North China Plain.
文摘In the area of recycling of spent chromated copper arsenate (CCA)-treated wood, most studies to date have focused on methods of removing/extracting the residual preservative from the wood matrix. It is well recognized that exposure of CCA-treated wood to an acid solution can reverse the CCA fixation process thereby converting the CCA elements into their water-soluble form. The economic viability of the process is enhanced because it can be integrated with other technologies and products (e.g., “green” spray foam insulation, etc.). The market for the “green” CCA is the same as for traditional CCA-the wood treating industry, principally utility poles and pilings. A market research study was conducted to determine the suitability of spent CCA-treated wood as a source for recycled, “green” CCA for manufacturing “green” spray-foam insulation. Specifically, we wanted to discern the attitudes and overall perspectives of buyers/sellers (i.e., utilities and wood treating companies) of CCA preservatives and treated wood products, disposal methods and costs for decommissioned CCA-treated wood, and understand perceptions of and willingness-to-pay for “green” CCA preservatives extracted from the technologies used in this research. Results show that 60% of wood preservative treating respondents and 60% of electric utility company respondents are somewhat or greatly interested in using out-of-service utility poles as feedstock for “green insulation” as part of a new potential business venture.
文摘This paper combines the application direction of bamboo vinegar in daily chemicals, focusing on the performance of bamboo vinegar raw materials from different sources in antibacterial, deodorization, antimycotic, etc. The results show that bamboo vinegar have a good antibacterial effect to the common Staphylococcus aureus and Escherichia coli, and also have obvious deodorant effect and a certain inhibitory effect on mold. However, under the certain low concentration, bamboo vinegar will play a role in promoting mold growth.
文摘Objective:To determine the anti-obesity effects of oolong tea on diet-induced overweight or obesity.Methods:A total of 8 g of oolong tea a day for 6 weeks was ingested by 102 diet-induced overweight or obese subjects.The body fat level of the subjects was determined at the same time by taking body weight, height and waist measurements.The thickness of the subcutaneous fat layer was also determined on the abdomen 3 cm to the right of the navel by the ultrasonic echo method.On the other hand,effects of oolong...
文摘The rotational frequency noise(also known as the pulsation noise) due to the mistuning of impeller blade rows introduced at the manufacturing stage of the impellers is observed in the small-sized centrifugal compressor for automobile turbochargers. The present paper addresses the elucidation of the generating mechanism and parameter dependency such as the kind and degree of mistuning. In order to analyze numerically the rotational frequency noise due to mistuning, the unsteady computational fluid dynamics(CFD) of the whole compressor including volute is executed, and the resultant time history of the pressure is fed into the spectral analysis.
文摘Since the automobile turbochargers are installed in an engine compartment with limited space, the ducts upstream of the turbocharger compressor may be curved in a complex manner. In the present paper, the effect of a curved duct upstream on performance of small centrifugal compressors for automobile turbochargers is discussed. The computational fluid dynamics (CFD) analysis of a turbocharger compressor validated for the compressor model with the straight pipe applied to the compressor with the curved pipe are executed, and the deterioration of the performance for the curved pipe is confirmed. It is also found that the deterioration of compressor performance is caused by the interaction of the secondary flow and the impeller.
基金supported by the National Key Research and Development Project[2020YFC1908904]Science and Technology Program of Xiamen[3502Z20193076]+1 种基金Natural Science Foundation of Fujian Province[2019J01135]Strategic Priority Research Program of the Chinese Academy of Sciences[XDA23020504]。
文摘In view of the risks induced by the inhibitory effects of applying impracticably large amounts of sewage sludge biochar(SSB)to the alkaline soil,this field study investigated the influence of moderate biochar amendments(0,1500,4500,and 9000 kg/hm2)on corn growth,alkaline soil properties,and the uptake of potentially toxic elements(PTEs).The results showed that applying more SSB would decrease the ammonium nitrogen concentration and increase the available phosphorus and potassium concentrations,which inhibited corn plant growth because of high background nutrient levels of the alkaline soil.When the alkaline soil was amended with 1500 kg/hm2 SSB,the dry weight of 100 niblets increased from 32.11 g in the control to 35.07 g.There was no significant variation in the total concentration of PTEs in the soil.The concentrations of Mn,Ni,Cu,and Zn in niblets decreased from 5.54,0.83,2.26,and 27.15 mg/kg in the control to 4.47,0.62,1.30,and 23.45 mg/kg,respectively.Accordingly,the health risk from corn consumption was significantly reduced.Furthermore,the combination of SSB and fertilizer improved corn growth and reduced the risk of consumption of PTEs.Therefore,considering the increase in corn fruit yield and the decrease in consumption risk,applying 1500 kg/hm2 of biochar to alkaline soils is a realistically achievable rate,which can broaden the utilization of SSB for remediation of different types of soil.
